Engine - Yamaha WR250F 2022 Owner's Service Manual

LUBRICATION SYSTEM CHART AND DIAGRAMS .......................................5-1
ENGINE OIL LUBRICATION CHART.........................................................5-1
LUBRICATION DIAGRAMS .......................................................................5-2
ENGINE REMOVAL ..........................................................................................5-6
REMOVING THE ENGINE .......................................................................5-10
INSTALLING THE ENGINE ......................................................................5-10
INSTALLING THE EXHAUST PIPE AND MUFFLER ...............................5-11
CAMSHAFT ....................................................................................................5-13
REMOVING THE CAMSHAFT .................................................................5-15
CHECKING THE CAMSHAFT ..................................................................5-16
CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET...........5-17
CHECKING THE TIMING CHAIN TENSIONERS.....................................5-17
CHECKING THE DECOMPRESSION SYSTEM ......................................5-17
INSTALLING THE CAMSHAFTS .............................................................5-17
CYLINDER HEAD...........................................................................................5-20
REMOVING THE CYLINDER HEAD ........................................................5-22
CHECKING THE TIMING CHAIN GUIDE (INTAKE SIDE).......................5-22
CHECKING THE CYLINDER HEAD ........................................................5-22
INSTALLING THE CYLINDER HEAD ......................................................5-22
VALVES AND VALVE SPRINGS ....................................................................5-25
REMOVING THE VALVES .......................................................................5-26
CHECKING THE VALVES AND VALVE GUIDES....................................5-27
CHECKING THE VALVE SEATS .............................................................5-28
CHECKING THE VALVE SPRINGS .........................................................5-29
CHECKING THE VALVE LIFTERS ..........................................................5-30
INSTALLING THE VALVES......................................................................5-30
CYLINDER AND PISTON ...............................................................................5-32
REMOVING THE PISTON........................................................................5-33
CHECKING THE CYLINDER AND PISTON.............................................5-33
CHECKING THE PISTON RINGS ............................................................5-34
CHECKING THE PISTON PIN .................................................................5-34
INSTALLING THE PISTON AND CYLINDER ..........................................5-35
GENERATOR..................................................................................................5-37
REMOVING THE GENERATOR ..............................................................5-38
CHECKING THE GENERATOR ...............................................................5-38
CHECKING THE WOODRUFF KEY ........................................................5-38
INSTALLING THE GENERATOR .............................................................5-38

ENGINE

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